1. Field of the Invention
The present invention relates to an ESD protection device for protecting a semiconductor device, etc. from electrostatic discharge failures, and a method for manufacturing the ESD protection device.
2. Description of the Related Art
In recent years, for the use of commercial-off-the-shelf appliances, there has been a tendency to increase the frequency of inserting and removing cables as input-output interfaces, and static electricity is likely to be applied to input-output connector areas. In addition, miniaturization in design rule with increase in signal frequency has made it difficult to create paths, and LSI itself has been fragile to static electricity.
Therefore, ESD protection devices have been used widely for protecting semiconductor devices such as LSI from electron-statics discharge (ESD).
As the ESD protection device described above, an overvoltage protection element having a porous structure part connected between a first electrode and a second electrode and produced by carrying out a firing treatment using a material of an overvoltage protection element which contains a non-conductor powder (silicon carbide powder), a metal conductor powder (Cu powder) and an adhesive (glass) is proposed.
In the case of the overvoltage protection element, however, addition of an adhesive (glass) is absolutely necessary, and therefore the following problems may occur.
(1) It is difficult to provide products of high reliability as variations in product characteristics tend to increase due to poor dispersion of glass.
(2) When ESD is applied repeatedly, the short circuit resistance tends to be degraded due to poor dispersion of glass.    Patent Document 1: Japanese Patent Application Laid-Open No. 2008-85284